Why can't OCR be perceived as a good example of AI?
Whenever a problem becomes solvable by a computer, people start arguing that it does not require intelligence. John McCarthy is often quoted: "As soon as it works, no one calls it AI anymore" (Referenced in CACM).

One of my teachers in college said that in the 1950's, a professor was asked what he thought was intelligent for a machine. The professor reputedly answered that if a vending machine gave him the right change, that would be intelligent.

Later, playing chess was considered intelligent. However, computers can now defeat grandmasters at chess, and people are no longer saying that it is a form of intelligence. 

Now we have OCR. It's already stated in another answer that our methods do not have the recognition facilities of a 5 year old. As soon as this is achieved, people will say "meh, that's not intelligence, a 5 year old can do that!"

A psychological bias, a need to state that we are somehow superior to machines, is at the basis of this.